Re: [PATCH][IPv6]: Fix incorrect length check in rawv6_sendmsg()
From: Sridhar Samudrala <hidden>
Date: 2007-03-30 17:47:08
On Fri, 2007-03-30 at 09:13 +0900, YOSHIFUJI Hideaki / 吉藤英明 wrote:
In article [ref] (at Thu, 29 Mar 2007 14:26:44 -0700 (PDT)), David Miller [off-list ref] says:quoted
From: Sridhar Samudrala <redacted> Date: Thu, 29 Mar 2007 14:17:28 -0700quoted
The check for length in rawv6_sendmsg() is incorrect. As len is an unsigned int, (len < 0) will never be TRUE. I think checking for IPV6_MAXPLEN(65535) is better. Is it possible to send ipv6 jumbo packets using raw sockets? If so, we can remove this check.I don't see why such a limitation against jumbo would exist, does anyone else? Thanks for catching this Sridhar. A good compiler should simply fail to compile "if (x < 0)" when 'x' is an unsigned type, don't you think :-)Dave, we use "int" for returning value, so we should fix this anyway, IMHO; we should not allow len > INT_MAX. Don't you think so? Signed-off-by: YOSHIFUJI Hideaki <redacted>
Acked-by: Sridhar Samudrala <redacted>
quoted hunk ↗ jump to hunk
diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c index 306d5d8..203e069 100644 --- a/net/ipv6/raw.c +++ b/net/ipv6/raw.c@@ -687,9 +687,9 @@ static int rawv6_sendmsg(struct kiocb *iocb, struct sock *sk, int err; /* Rough check on arithmetic overflow, - better check is made in ip6_build_xmit + better check is made in ip6_append_data(). */ - if (len < 0) + if (len > INT_MAX) return -EMSGSIZE; /* Mirror BSD error message compatibility */diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 0ad4719..f590db5 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c@@ -615,7 +615,7 @@ do_udp_sendmsg: return udp_sendmsg(iocb, sk, msg, len); /* Rough check on arithmetic overflow, - better check is made in ip6_build_xmit + better check is made in ip6_append_data(). */ if (len > INT_MAX - sizeof(struct udphdr)) return -EMSGSIZE; --yoshfuji -To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html